In the prior art, the use of baggage pushers to remove select pieces of baggage that travel along a conveyor are well known. U.S. Pat. No. 4,564,105 to Brouwer et al. discloses a tilted spiral article diverter having a spiral shaped sweep which is rotated to cause it to engage selected articles on a conveyor and push them off laterally. The sweep is supported on and rotated by a shaft which is inclined to the vertical and toward the conveyor whereby the circular path traced by its outer end is in an inclined plane. As it moves to its retracted position, the sweep moves upwardly. Since the free end of the sweep moves upwardly rather than laterally when the sweep is retracted, the total floor area occupied by the equipment is reduced without sacrificing the operating principles of the invention. This is an improvement over devices which occupy large areas in a conveyor system, such a luxury not available in certain industries, e.g., the airlines.
Brouwer et al., acknowledging a deficiency in the pusher design in catching or trapping soft sided baggage between the sweep and the conveyor, disclose a second embodiment wherein the shaft of the sweep is inclined both laterally towards the conveyor axis and towards an upstream direction of the conveyor, see FIGS. 7-10A and 13 thereof. In this embodiment, the face of the sweep is more to the side of the article rather than in front of it to reduce the tendency of the sweep to move over or trap any portion of the article between the sweep and the conveyor.
In either of the embodiments of the Brouwer et al. patent, there still remains a sizable gap between the sweep and the conveyor as a result of the inclined axis of the sweep shaft of rotation. This gap still provides the possibility of trapping or catching soft sided baggage during the sweep action. As a result, there exists a need for an improved baggage pusher which overcomes the drawbacks of the pusher disclosed in the Brouwer et al. patent.
High speed start-stop devices such as baggage pushers are often driven by motors utilizing clutch-brake mechanisms. These types of mechanisms are often noisy, require high maintenance and operate with discontinuous or jerky motions. Other types of baggage pushers, such as a Logan-Glidepath CamSort.TM. diverter made by Fabricom of Belgium, can strike a piece of baggage at a point on the pusher at a high velocity which can cause baggage damage. Accordingly, there exists a need for improved drives and designs for these types of devices.
In response to the drawbacks of prior art designs related to baggage pusher devices and the need for improved baggage pushers, the invention provides an improved baggage pusher device which overcomes the problems associated with prior art designs. The inventive pusher minimizes trapping of soft sided baggage, provides a low maintenance, quiet and smoothly operating drive and minimizes damage to baggage due to high velocity contact by the pusher device.